Bone Anchored Hearing Aid (BAHA)

What is BAHA?

Bone Anchored Hearing Aid (BAHA) is a device that transmits sound energy through vibration of the skull, bypassing the eardrum and the middle ear hearing bones. Skull vibration will lead to the compression and the expansion of the inner ear and a perception of sound.

BAHA is indicated in two groups of patients who are unable to utilize a conventional hearing aid:

1. Conductive (mechanical) hearing loss
   • Those with congenital aural atresia.
   • Those with mastoid cavities and chronic infection made worse by hearing aids.
     
     
2. Nerve hearing loss
   • Those who have single-sided deafness from surgery (i.e., acoustic neuroma excision, labyrinthectomy), injury, viral induced deafness, among others.

Adequate inner ear function (cochlear reserve) is important for the success of this device. A trial using a bone conduction device prior to surgery is important in establishing performance and satisfaction.

How does BAHA work?

A titanium implant (screw) is placed behind the ear through a small operation. The implant is placed about 4 mm into the outer table of the skull; it is allowed to integrate into the bony tissue over a 3-4 month period. The skin/scalp surrounding the screw is thinned out to optimize this process.

Once the implant is firmly attached to the skull, an external sound processor/bone conductor is applied and turned on.

What does BAHA look like?

View images of BAHA »

Connector (abutment) poking through the skin

BAHA attached to the connector

BAHA fitted onto the implant

The operation

The operation is performed at Sunnybrook's Bayview Campus, usually under general anaesthesia (though it can also be performed under local anaesthesia with sedation), on an out-patient basis.

• A dressing and a healing cap is applied for two weeks
• Dressing and sutures are then removed to allow aeration of the skin flap
• Antibiotic ointment is applied for a few weeks
• There will be a small area of hair loss in the skin flap around the titanium implant

Risks

• Minor wound infection: granulation tissues are common; proper wound care is important
  
  
• Failure to achieve osseointegration leading to the loss of the titanium implant - <5%
  
  
• Skull infection: rare
  
  
• Brain fluid (CSF) leakage: rare

BAHA fitting and ongoing care

After the implant has osseointegrated into the bony tissue (3-4 months), you will return to audiology services to receive your BAHA sound processor. During the appointment, you will receive an orientation of the BAHA use and function. Objective testing will also be completed at this appointment to ensure that you are getting benefit from the BAHA sound processor.

The skin surrounding the implant site and the implant itself will require ongoing maintenance. A special cleaning brush will be provided for this purpose at the fitting appointment.

Fees/funding

Currently, the provincial health plan does not cover the costs for the internal implant or the sound processor, though Sunnybrook's otolaryngology department is currently able to fund the cost of the BAHA implant. However, the cost of the external sound processor is the responsibility of the patient and is to be paid at the fitting appointment.

Payments for the external sound processor are to be made to Sunnybrook Audiology Services. We accept cash, personal cheques, debit, and VISA. If you have extended health-care coverage, please inquire with your insurance company to see if your plan covers the BAHA system.

The BAHA sound processor comes with a two-year manufacturer warranty. The BAHA sound processor operates using batteries that need to be replaced on a weekly to bi-weekly basis. The cost of the batteries is the responsibility of the patient.

The Assistive Devices Program does not provide funding towards an initial BAHA system. The Assistive Devices Program will fund up to 75 per cent of the cost of a replacement sound processor to a maximum of $2625.

How do I know if I'm a candidate?

If you believe you are a candidate for BAHA, ask your family doctor to refer you to Dr. Joseph Chen, Dr. Julian Nedzelski, and Dr. Vincent Lin for an assessment.

You may also contact Audiologist Gloria Camacho at gloria.camacho@sunnybrook.ca.

Once the referral is recieved, you will be scheduled for an audiogram to determine if you are a suitable candidate for a BAHA. At this appointment, you will have the opportunity to listen to the BAHA on a test band.